Apparatus for producing imprints on paper or the like



June 11, 1968 o. SCHNEIDER ET AL 3,387,371'

APPARATUS FOR PRODUCING IMPRINTS ON PAPER OR THE LIKE Filed Dec. 2, 1966 3 Sheets-Sheet 1 INVEN TOR.

OTHMAR SCHNEIDER y WOLFGANG VIEHRIG June 11, 1968 Q scHNElDER ET AL 3,387,371

APPARATUS FOR PRODUCING IMPRINTS ON PAPER OR THE LIKE I5 Sheets-Sheet 2 Filed Dec. 2, 1966 Fig.2

INVENTOR,

OTHMAR SCHNElDER WOLFGANG VIEHRIG A he June 11, 1968 o. SCHNEIDER ET AL 3,387,371

APPARATUS FOR PRODUCING IMPRINTS ON PAPER OR THE LIKE Filed Dec 2, 1966 3 Sheets-Sheet 3 Fig.3

7d q 78g 30 K l I 17 5 Fig.4

INVENTOR.

OTHMAR SCHNEIDER By WOLFGANG VIEHRIG United States Patent 0 ABSTRACT OF THE DISCLOSURE Apparatus for applying graphite marks to sheets comprises a holder which carries a graphite wheel and is rockable to move the wheel into and away from engagement with a sheet. The wheel is rotated during engagement with the sheet to produce a sharply outlined mark.

The present invention relates to improvements in apparatus for producing imprints or marks on strips of lightsensitive paper or similar sheet-like or band-like carriers. More particularly, the invention relates to apparatus which may be utilized to produce imprints on sensitised sheets of paper or the like in photographic copying machines, especially to produce imprints by engagement of carriers with graphite wheels.

It is already known to provide a photocopying machine with an apparatus which can produce imprints on sensitised paper. Such imprints are normally made by contacting the paper with a wheel which consists of graphite. The imprints are then tracked by detectors which scan the paper for conductivity and trigger the operation of a cutting or severing mechanism which subdivides the paper into prints or snapshots of desired size. The cutting operation is carried out by automatic machinery and takes place subsequent to completed treatment of paper in a developing bath. It was found that the operation of presently known marking apparatus in such photographic copying machines is not entirely satisfactory, mainly because the imprint producing wheels undergo non-uniform wear and have a very short useful life. This is attributed to the fact that the wheels are caused to strike against the carrier with a force which is excessive in view of the brittleness of graphite. Furthermore, conventional marking apparatus are rather bulky and the imprints or marks produced by such apparatus are not always black and their outlines are not sufiiciently sharp. Sharp definition of marks or imprints is very important, especially when several marks of different size and/ or shape are applied close to each other and must be located by two or more different detectors.

It is an important object of our invention to provide a marking apparatus which can be used in presently known photocopying machines and which can produce sharply defined marks while simultaneously insuring uniform wear on the imprint producing element or elements.

Another object of the invention is to provide a marking apparatus which can be operated in a fully automatic way and protects the imprint producing element or elements against such stresses which are likely to result in chipping, cracking or total destruction of imprint producing elements.

A further object of the invention is to provide a marking apparatus which utilizes one or more graphite wheels and wherein such wheels can leave sharply defined, rectangular and truly black imprints in automatic response to engagement with a sheet-like carrier.

An additional object of the instant invention is to provide a marking apparatus which requires a single prime mover and wherein the application of imprints takes place in a plurality of stages.

Still another object of the invention is to provide a novel system of motion transmitting members which can be used in the improved marking apparatus to move the imprint producing element or elements with reference to a strip of light-sensitive paper or another sheetor bandlike carrier.

A concomitant object of our invention is to provide a marking apparatus which occupies little room and whose energy requirements are low.

Briefly outlined, one feature of our invention resides in the provision of an apparatus for applying imprints to sheet-like carriers, particularly for applying truly rectan gular graphite marks to light-sensitive paper or the like. The apparatus comprises support means which may be constituted by the frame of a photographic copying ma,- chine, output means rotatably mounted in the support means, holder means pivotably mounted on the support means, an imprint producing wheel which preferably consists of graphite and is rotatably mounted on the holder means, rocking means for pivoting the holder means from a first position to a second position in response to rotation of the output means in a predetermined direction to thereby place the imprint producing wheel into actual engagement with a carrier, clutch means for rotating the wheel in response to rotation of the output means, preferably with such a delay that the wheel begins to rotate at the time when or shortly after the holder means reaches the second position, and prime mover means for rotating the output means in predetermined direction.

The prime mover means preferably comprises an electromagnet whose armature is constituted by the output means. The control circuit of the electromagnet may include means enabling the electromagnet to transmit to the output means a higher torque after the imprint producing wheel has been moved into actual engagement with the carrier. This protects the wheel against excessive stresses. Also, rotation of the wheel with reference to the carrier will enable the wheel to produce sharply defined and truly black rectangular marks which can be readily detected to initiate the operation of a suitable cutting mechanism.

The novel features which are considered as characteristic of the invention are set forth" in particular in the appended claims. The improved marking apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawings, in which:

FIG. 1 is a somewhat schematic side elevational view of a marking apparatus which embodies one form of the present invention, the holder means for the imprint producing wheel being shown in a first or idle position;

FIG. 2 is a similar side elevational view but showing the holder means in a second or operative position;

FIG. 3 illustrates the control circuitfor the prime mover means of the apparatus shown in FIGS. 1 and 2; and

FIG. 4 illustrates a modified control circuit.

Referring first to FIGS. 1 and 2, there is shown a support 1 constituted by the frame of a known photographic copying machine, for example, a roller copier. This machine embodies the marking apparatus of our present invention, the apparatus including a back support or platform 2 for sheetlike carriers 3 of light sensitive material. For example the carrier shown in FIGS. 1 and 2 may be constituted by strip of photographic paper. The support 1 comprises a bracket 4 disposed at a level above the back support 2 and serving to carry the majority of components of the improved marking apparatus. Thus, the bracket 4 supports the housing of an electromagnet 5 which constitutes the prime mover of the marking apparatus and has an armature in the form of an output shaft 6 which is rotatable about a horizontal axis. The output shaft 6 is directly connected with a lever 7 which forms part of a rocking unit and carries a horizontal pivot pin 8 for the pawl 9 of a one-way clutch further including a ratchet wheel 13.

The bracket 4 (or the housing of the electromagnet 5) supports an elongated holder or arm 10 which is turnable about the axis of a horizontal pivot 10a and whose free end carries a horizontal shaft 12 for the ratchet wheel 13 and for an imprint producing or marking wheel 11 made of graphite. The ratchet wheel 13 is fixed to and can rotate the wheel 11 in response to rotation of the output shaft 6 in a counterclockwise direction, as viewed in FIGS. 1 and 2. The aforementioned rocking unit further comprises an elongated guide bolt 14 which is rotatably coupled to an intermediate portion of the arm 10 and extendsslidably through a slot provided in a lug 7a of the lever 7. A relatively strong resilient element 15, here shown as a helical expansion spring, operates between the lug 7a and a shoulder 10:: on the arm 10 and tends to move the lever 7 to the position shown in FIG. 1, i.e., to rotate the lever 7 in a clockwise direction. A second resilient element 16, represented by a relatively weak torsion spring, operates between a collar 7b of the lever 7 and a bent-over lug 10b of the arm 10 and tends to maintain the arm 10 in the raised or idle position shown in FIG. 1. The pivot 10a is mounted on the bracket 4 or on the housing of the electromagnet 5.

The operation is as follows:

When the carrier 3 is moved to a predetermined posi tion with reference to the back support 2, the electromagnet 5 is energized and rotates the output shaft 6 in a counterclockwise direction. The lever 7 rotates with the output shaft 6 and its lug 7a causes the relatively strong spring 15 to pivot the arm 10 in a counterclockwise direction whereby the spring 15 overcomes the opposition of the weaker spring 16. This moves the arm 10 to the second or operative position shown in FIG. 2 in which the wheel 11 engages a selected portion of the carrier 3. Thus, the back support 2 is positioned in such a way that it automatically arrests the arm 10 in operative position.

The electromagnet 5 continues to rotate the output shaft 6 whereby the shaft 6 continues to turn the lever 7 which compresses the spring 15 and causes the pawl 9 to rotate the wheels 11 and 13 through a preselected angle. Such rotation of the ratchet wheel 13, while the wheel 11 is in actual contact with the carrier 3, will provide the carrier with a sharply defined rectangular mark which is entirely black and can be readily detected for the purpose of insuring that the carrier will be severed in a desired way. The manner in which the marks or imprints produced by graphite wheel 11 can be detected by means which determine the conductivity of various areas of the carrier 3 forms no part of our present invention.

When the electromagnet 5 is deenergized, the spring 15 expands first and turns the lever 7 in a clockwise direction so that the pallet of the pawl 9 rides over several teeth of the ratchet wheel 13. This is desirable to insure that the periphery of the wheel 11 wears away uniformly. The spring 16 begins to dissipate energy upon completed expansion of the spring 15 whereby the arm 10 pivots in a clockwise direction and returns to the raised or idle position of FIG. 1. Stops 7c and 10c respectively arrest the lever 7 and arm 10 in idle position. The spring 15 stores energy when the output shaft 6 continues to rotate in a counterclockwise direction after the periphery of the wheel 11 has been moved into actual engagement with the carrier 3.

It is desirable to operate the marking apparatus in such a way that the torque transmitted by electromagnet 5 to its output shaft 6 is relatively weak when the arm 10 is pivoted from idle to operative position. This insures that the relatively brittle wheel 11 is not damaged on impact against the carrier" 3. Such torque is thereupon increased to insure that the wheel 11 will actually rotate with reference to the carrier 3 and will leave a clearly defined and entirely black rectangular mark thereon. FIG. 3 illustrates a first control circuit which can be utilized to regulate the torque upon the output shaft 6 during energization of the electromagnet 5. This control circuit comprises a source 30 of DC current connected in series with the winding of the electromagnet 5, a resistor 13 and a normally open master switch 17. The latter is closed in a well known manner by a trip which is actuated when the carrier 3 assumes a predetermined position with reference to the raised graphite wheel 11. Closing of the master switch 17 results in energization of the electromagnet 5 whereby the output shaft 6 rotates in a counterclockwise direction, as viewed in FIG. 1, and causes the rocking unit including the lever 7 and spring 15 to move the arm 10 from the idle position of FIG. 1 to the operative position of FIG. 2. When the lever 7 reaches the position shown in FIG. 2, its trip 7d closes a normally open second switch or control switch 19 which is connected in parallel with the resistor 18 so that the circuit of the electromagnet 5 is then completed across the switches 17 and 19 and the current need not flow through the resistor 18. The stronger torque which is now produced by electromagnet 5 is used to rotate the output shaft 6 while the wheel 11 engages the carrier 3 whereby the pawl 9 rotates with reference to the lever 7 and turns the ratchet wheel 13 which, in turn, rotates the wheel 11 with reference to the carrier. The switch 19 opens automatically in response to opening of the switch 17 which latter then deenergizes the electromagnet 5 and enables the spring 15 to expand. Such expansion of the spring 15 moves the lever 7 from the position shown in FIG. 2 so that the trip 7d releases the switch 19. The trip 7d can be mounted on the arm 10 or on the pawl 9 in such position that the switch 19 is closed on movement of the arm 10 and pawl 9 to the positions shown in FIG. 2.

For example, the master switch 17 may be closed by a timer mechanism (not shown) of the copying machine and remains closed for an interval of /2 second. The first part of such interval is used up to move the arm 10 to operative position and the remaining part is used up to rotate the wheel 11 with reference to the carrier 3.

FIG. 4 illustrates a modified control circuit which can replace the circuit of FIG. 3. The manner in which the electromagnet 5 is connected in series with the master switch 17, resistor 18 and energy source 30 is the same as in FIG. 3. The switch 19 is replaced by a control switch 20 which is constituted by a diode, preferably a thyristor, and is connected in parallel with the resistor 18. The control grid of the diode 20 is connected with one terminal of a Zener diode 23 forming part of a timedelay circuit for the diode 20. The other terminal of the Zener 23 is connected to a tap between the elements 21, 22 of an R-C link which is connected in parallel with the diode 20 and resistor 18. A further capacitor 24 is connected between the ground and the grid of the diode 20. The purpose of the capacitor 24 is to bring about short-lasting flow of current through the diode 20 in response to a sudden drop in potential. It will be seen that the diode 20 performs the same function as the control switch 19 of FIG. 3, with the exception that it disconnects the resistor 18 with a predetermined delay following closing of the master switch 17. Such delay is determined by the R-C link 21, 22 and Zener diode 23. The delay determined by the unit 21-23 is selected in such a way that the wheel 11 already rests still on the carrier 3 when the diode 20 begins to conduct current in order to transmit a strong torque to the output shaft 6 of the electromagnet 5 and to cause rotation of the Wheel 11 with reference to the carrier.

If the marking apparatus of our invention comprises two or more graphite wheels 11, the control switch 19 of FIG. 2 or the time delay unit 21-43 of FIG. 4 may be used to control the energization of two or more electromagnets. For example, a series of carriers 3 may be advanced simultaneously and each such carrier may be provided with markers by means of a separate wheel 11.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is:

1. Apparatus for applying imprints to sheet-like carriers, particularly for applying graphite marks to lightsensitive strips of paper or the like, comprising support means; output means rotatably mounted in said support means; holder means movably mounted on said support means; an imprint producing wheel rotatably supported by said holder means having a continuously turned peripheral printing face; moving means for moving said holder means from a first position to a second position in response to rotation of said output means in a predetermined direction and for thereby moving said wheel into engagement with a carrier; means for rotating said wheel in response to rotation of said output means so that the wheelrotates during engagement with a carrier with said continuously curved peripheral face sliding during such rotation on said carrier in engagement therewith so as to make a clearly visible imprint; and prime mover means for rotating the output means in said predetermined direction.

2. Apparatus as defined in claim 1, wherein said prime mover means comprises an electromagnet mounted on said support means and saidd output means constitutes the armature of said electromagnet.

3. Apparatus as defined in claim 1, further comprising means for permanently biasing said holder means to first position.

4. Apparatus as defined in claim 1, wherein said moving means comprises a spring.

5. Apparatus as defined in claim 1, further comprising a back support for sheet-like carriers, said back support being positioned to prevent further movement of said holder means beyond said second position by bodily engagement of a carrier on said back support with said wheel.

6. Apparatus as defined in claim 1, wherein the holder means is pivotable about an axis parallel with the axis of said wheel and the axis of said output means.

7. Apparatus as defined in claim 1, wherein said wheel consists of graphite and the means for rotating said wheel comprises a one-way clutch.

8. Apparatus as defined in claim 1, wherein the means for rotating said wheel is operative only upon completed movement of said holder means to second position.

9. Apparatus for applying imprints to sheet-like carriers, particularly to applying graphite marks to lightsensitive strips of paper or the like, comprising support means; output means rotatably mounted in said support means; holder means pivotably mounted on said support means; an imprint producing wheel rotatably supported by said holder means; a back support for sheet-like carriers; rocking means for pivoting said holder means from a first position to a second position in response to rotation of said output means in a predetermined direction, said back support being positioned to prevent further pivoting of said holder means beyond said second position by bodily engagement of a carrier on said back support with said wheel and said rocking means comprising a lever fixed to said output means and spring means interposed between said lever and said holder means to pivot said holder means in response to rotation of said lever with said output means until said wheel engages a carrier on said back support; means for rotating said wheel in response to rotation of said output means, comprising a ratchet coaxially secured to said wheel and a pawl pivotally supported by said lever and arranged to turn said ratchet and said Wheel in response to further rotation of said output means on engagement of said wheel with a carrier on said back support; and prime mover means for rotating said output means in said predetermined direction.

10. Apparatus for applying imprints to sheet-like carriers, particularly for applying graphite marks to lightsensitive paper or the like, comprising support means; output means rotatably mounted in said support means; holder means pivotably mounted on said support means; an imprint producing wheel rotatably supported by said holder means; rocking means for pivoting said holder means from a first position to a second position in response to rotation of said output means in a predetermined direction; a back support for sheet-like carriers, said back support being positioned to prevent further pivoting of said holder means beyond said second position by bodily engagement of a carrier on said back support with said wheel; means for rotating said wheel in response to rotation of said output means; prime mover means comprising an electromagnet for rotating said output means in said predetermined direction, said output means constituting the armature of said electromagnet; and a control circuit for said electromagnet, including a source of electrical energy, resistor means connected in series with said source and said electromagnet, and normally open control switch means connected in parallel with said resistor means and arranged to close in response to movement of said holder means to second position thus enabling said electromagnet to transmit to said output means a stronger torque and to rotate said wheel while the latter engages a carrier on said back support.

11. Apparatus for applying imprints to sheet-like carriers, particularly for applying graphite marks to lightsensitive strips of paper or the like, comprising support means; output means rotatably mounted in said support means; holder means pivotably mounted on said support means; an imprint producing wheel rotatably supported by said holder means; rocking means for pivoting said holder means from a first position to a second position in response to rotation of said output means in a predetermined direction; a back support for sheet-like carriers, said back support being positioned to prevent further pivoting of said holder means beyond said second position by bodily engagement of a carrier on said back support with said wheel; means for rotating said wheel in response to rotation of said output means; prime mover means comprising an electromagnet for rotating said output means in said predetermined direction, said output means constituting the armature of said electromagnet; and a control circuit for said electromagnet, including a source of electrical energy, resistor means connected in series with said electromagnet and said source, normally open control switch means connected in parallel with said resistor means, and time delay means for closing said control switch means with a predetermined delay following energization of said electromagnet thus enabling said electromagnet to transmit to said output means a stronger torque and to rotate said Wheel while the latter engages a carrier on said back support.

12. Apparatus as defined in claim 11, wherein said control switch means comprises a diode.

13. Apparatus as defined in claim 11, wherein said control switch means comprises a thyristor.

14. Apparatus as defined in claim 11, wherein said control switch means comprises a first diode connected in parallel with said resistor means and said time delay means comprises an R-C link connected in parallel with said first diode and a Zener diode having a first terminal connected with the grid of said first diode and a second 7 terminal connected with a tap between the elements of said R-C link.

15. Apparatus as defined in claim 7, wherein said control circuit further comprises capacitor means connected between the ground and the grid of said first diode.

16. Apparatus for applying imprints to sheet-like carriers, particularly for applying graphite marks to light sensitive strips of paper or the like, comprising support means; output means rotatably mounted in said support means; holder means pivotably mounted on said support means; an imprint producing wheel rotatably supported by said holder means; rocking means for pivoting said holder means from a first position to a second position in response to rotation of said output means in a predetermined direction; means for rotating said Wheel in response to rotation of said output means; prime mover means for rotating said output means in said predetermined direction; first resilient means for permanently biasing said holder means to first position; and a back support for sheet-like carriers, said back support being positioned to prevent pivoting of said holder means beyond said second position on bodily engagement of a carrier on said back support with said wheel, said rocking means comprising second resilient means operating between said output means and said holder means to pivot said holder means from a first to a second position against the 0pposition of said first resilient means in response to rotation of said output means.

References Cited UNITED STATES PATENTS HARRY N. HAR-OIAN, Primary Examiner. 

